Reflector + collimator = reflective collimator

It's already more than 10 years ago. One day, I got curious... Collimator lens vs reflector, which one would be better? Regarding this question, I think I am not alone, because I could find some other threads related to the same question.

It was a very hard-to-answer question, so the solution I found was having them together. To this end, a thin layer of aluminum was vapor deposited on the back of collimators. In the next figure, the left hand side is an aluminum deposited collimator, and the right hand side is a normal collimator.

unfortunately, this project was not so successful, because I didn't see any noticeable improvement of brightness even after the aluminum deposition. Maybe, that is because the backside leakage of collimators is quite negligible.

UCO Clarus, my new backpacking gadget!

After getting back from a long hike to Rae Lake Loop, I thought I need a small light weight LED lantern. After some research, I decided to purchase a UCO Clarus lantern, and now I am so happy with that. It just weighs about 2 ounces and super bright. A little downside is that its burn time is less than 2 hours in its high-mode (150lm). However, this is not a downside at all in fact, because it can be easily overcome by using a high capacity Li-ion battery in place of original 3AAA batteries. A 22500 Li-ion battery (2300mAh) nicely fits UCO Clarus as if originally designed for it, and provides about 5 hours' burn in the high-mode - it's more than enough for two days' backpacking trip.

 

Left - 3AAA, right - 22500 Li-ion

Left - 18500 Li-ion with spacers (18-22 O-rings), right - 22500 Li-ion